Furnace.



V, MACKAY,

FURNACE.

APPLICATION FILED AUG.21.1913.

2 SHEETS-SHEET 2.

@www isral-'ins earner orare z l Vas-1L MACKAY, or Bestron,4 MASSACHUSETTS.

EURNACE.

mareos.

T 0 all ttf/rom it mayv coizcem l .Be it known .that I, VAsiL MACKAY, a citizen of the United States, residing at Boston,

in' the county of Suffolk and State. of' Massachusetts, have invente'd an Improvementin Furnaces, of which the following is a specification.

This invention relates 'to certaln improveburn coal or col e,and more particularly to certain im ro'vements in means for feeding the fuel tothe grate and'l spreading 1t there. `over.-`

Prior to my invention various automatic automatic Vdevice has been prduced which will maintain the fuel at a predetermined. :zol

depth, under all conditions, and during the various fluctuations of the demands -of th boiler which ordinarily occurs.

The object of my invention 1s to provide automatic means for supplying fuel to the furnace grate, distributing it thereover toa uniform depth and maintainingl it at this depth under all conditions, 'so that all variations in rapidity compensated 'fon A further obJect of I my invention is to provide means for breaking up and dumping tf consumption will be Y the clinkers at 'the rear Aend of the grate, so

that the use of hand implements for that.

purpose is made unnecessary and the employment of a long grate surface is made practical.

l 'accomplish these objectsby the means shown in the accompanying drawing, Vin which,

Figure lis'a sideielevation, partly in section, showing an ordinary-steam boiler provided with a grate and fuel feeding devices made according to my invention.v Fig.

Specicaton of Letters Patent. Pafmteail Atag.; 24, application med augustzai, 1913.- 1 sentire. 785,@58.

. l Y grate-bars. FigfS'is anenlarged sectional type, provided with'my invention, l indicating the front wall of the furnace, and 2 the boiler supported above the furnace in the -devices have been produced for feeding the fuel from the front` to the rear ofthe furnace, bu t,-so far as I am aware, no strictly 2 is a plan viewof the furnace grate. Fig. 3 i

is a front elevation, showing the operating y mechanism. Fig. i is a detail front view of the grate operating mechanism. Figs. 5 and 6 are detail views partly in section of the grate bars. and'their operating means,

Fig. 7 is a detail l,front view of one of the I usual manner.

. According to'my invention l provide the furnace with two sets of grate-bars 3 and d, the bars 3 being arranged alt rnately with the bars and all y"of said bars being arranged in the position usually occupied by the grate in furnaces of'this'character, and,

VWhile two separate series of grate-bars are shown in Fig. 2, it will be obvious that, so far as my .invention is concerned,',it .is im: material how many series are employed. The' grate-bars are arranged to extend transversely' of thefurnace, or parallel to the front wall thereof, and normally present an approximately horizontall surface. as is customary, said bars being identical'inform., the separation into sets being made for convenience in` description. Said grate-bars are each approximately of sector shapein cross-section and have a segmental shaped front side. the upper and. lower sides ther-el of extending convergently fromv the edges of said front side and terminating in a rounded, or shaftelike rear portion which is extended beyond the ends'of the bar to provide. end trunnions 3', orhl, as shown in Figs. 2 and .6, the whole,being cast integrally. The upper surface of each grate-bar is arranged to extend tangentially' from said rounded .rear portion` and the. segmental shaped front slde 1s curved on angrc having the axial line of said trunnions as a center` 'ee i on their trunnions, as hereinafter described. With this arrangement, when either bar is swung on its trunnions, this space between the front side of one bar and the rear'side of the next adjacent bar will not be appreciably increased diminished, and, as the upper surface of each grate extends tangentially to the surface of its rounded rear side portion, which is continuous with the surface of the tru'nniom. when the grate is swung on its trunnions from a Vhorizontal posit-ion, upwardly and away from the front of the furnace, substantially its entire upper surface will be raised. Each grate-bar is also provided with transversely extending vdraft slots t which extend vertically therethrough from the upper to the lower side, and also with draft slots Z) of similar size in the front face thereof which lead to the of any grate bar is in horizontal position, its

corresponding arm will be then depended therefrom nearly vertically.

A rod 7 is connected to the arms 6, and a rod 8 is connectedl to the other arms 6'-, so that, when the rod 7 is drawn forwardly, or moved longitudinallyv toward the front of the furnace, all of the grate-bars 3 will be swung upwardly on their trunnions and,

when the rod 8 is drawn forwardly, all of the grate-bars 4 will likewise be swung upwardly. iVith this arrangement one set of alternate grate-bars only may be swung upwardly at one time, by moving one rod, and then the others may be likewise moved, or all of them may be thus moved together by moving both rods together, or by connecting all of the arms to one rod, and it will be obvious that the rods 7 and 8 may be operated mechanically or manually in any relative time desired. However, as I secure results by operating them alternately which 1 cannot secure by operating them together, I preferablyl provide suitable mechanical means for this purpose. Such mechanical means preferably comprises a main shaft 9 vwhich may be constantly driven from any suitable source, and an operating shaft 10 which is mounted adj acently, and on which a gear 10 is provided which is arranged in mesh with a gear 9 on shaft 9, said shafts being preferably arranged in a chamber formed in the front wall of the furnace, as-

shown. A pair of collars 12, 12 having 'fingers 13, 13, respectively, thereon, areiadforwardly, causing arms G to be swung inthesame direction and the grates 4 to be swung upwardly, and rearwardly, as shown in Fig. 1. After the rod 7 has been drawn forward to a certain extent, the finger 13 will become disengaged from said lug, so that the gratebars 3 will be free to swing down by the action of their own weight, and

by thaty of the fuel thereon, to their normal positions. This operation will take place during one half a revolution of shaft 10 and during the other half of the revolution the other set of bars 4 will be operated in like manner as will be obvious. Any suitable means to limit the downward movement 0f the bars at the horizontal position may be provided on said rods 7, 3, which limits'its rearward movement, as'by providing stoppins, as 15, thereon, which engage the rear wall of the chamber containing said shafts 9 and 10. The extent to which the bars 3 and 4 may be swung upward may be varied by adjusting the lugs 14, 14 longitudinally of the rods on which they are mounted. A fuel hopper 17 is arranged on the front side of the furnace and leads to a chamber 18 in the front wall thereof, and a fuel feeder 19 is arranged in the bottom of said' chamber,

said device being imperforate, but of simi-' lar shape to said grate-bars, and being similarly pivoted at its ends on trunnions` 20, the rear side of said feeder being arranged directly in front of, and at a short distance -from the frontl side of the first grate-bar 3.

Said feeder is likewise provided with an arm 21, which depends therefrom and is arranged to be engaged by one or more lugs 22, which project laterally from collar 12 and may be cliametiically, or .otherwise disposed thereon, so that, as the shaft 10 is rotated said lugs will engage said arm 21 and swing it forwardly from the dotted line position of Fig. 6 to the full line position i thereof, thus causing the front portion of the feeder to'be swung upwardly in a manner similar to that in which the grate-bars are operated, as previously described. The shaft 10 serves as a stop to limit the rearward swinging movement of arm 21.

A clinker-brelaking and dumping gratebar 23 is pivotally mounted on trunnions 24 between the rear grate bar 4 and the rear' Wall ofy the furnace, said trunnions being l0- cated .attlie front side thereof adjacent lthe trunnlo'ns f said grate-bar'l, -aSshoWn in Fig. 1. An arm 25 is-connectedthereto, and i extends rv dially l with relation to the-trun-.

fuel-retaining abutment. 28 'directly inthe rear of the grae-bar 23.

Th operation of my device isv'aslfollows:

'F e having been introduced into the hopper 1 it falls into the chamber. l8 upoii the eeder 19,' and, as said-feeder'i's swung up y the action of shaft it will'throw reare l wardlw7 the fuel on the next adjacent g atebe delivered rom one bar tothenext until.

bar. while the latter is in horizonta or nearly horizontal position, and then the fuel, which is4 thus discharged `on ,the 'first grate-bar, will be discharged onthe A,one next 'succeeding a d in like manner the fuel will it reachestlie rear end of the furnace, where it will-be delivered onto the dumping grate'- bar 23, and, then will be piled thereon against the abutment 28. The fuelvis ,thus fed ov'er the ent-ire grateL'surface, andgisrconsumed as itis fed to the rear, anld, ordinarily, all irnpuritieswill tie-'delivered ontlie rear-bar 23, where they will be dumped whennecessary.

By the above described .operation a 'unif -forin distribution of the fuel over the yentire grate-surface isf secured, and the fuel is lmaintained, practically, at a uniform depth throughout saidsurface, said-depth dependilng on the width of the grate-bars andV their range of. movement from the horizontal. Tliat is, under certain given conditions itis impossible for. a grate t0 conv'ey the fuel forward when the depth of the fuel in front,

of it has reached a certain point, for the real'sonthat when tliebar'is raised, it will be 4prevented from delivering the fuel to the next bar by the 'fuel thereon, so that the f uel will reiiiain thereon and be returned to its previous position when the ba-r is lowered. One grate-bar will thus feed along the fuel to the next -when the depth of the bed of fuel is less than the maximum point, but will not feed it along when its depthhas reached -tliis point. In case the fuel is consumed faster at one side of the furnace than at the other, thefuel willbe fed correspondingl)v faster at 'the oneside than at the other, In the ordinary operation of the furnace, therefore. the grate-bars will feed the fuel fan-wardly until it begins to accumulate on the hack-har and becomes piled against' the rear wall This operation will continue until the fuel on the back-bar 23 ewflies'sucli a depth that it prevents the feeding har l from feeding more fuel back onto said ,bar 23 and this bar 4. then becomes filled to the 'same' depth', andthen' in like manner. the succeeding bJars fromv rearto front'become filled to a like depth successively,and when me front bar 3 be comes filled, vthe fuel thereohiwill prevent vthel feeder 19 from delivering more fuel fromthefuel chamber ont said front bar.

The -grate will 'thus be co ered to the d- ,v sired depth from rear to front and the fuel will only be fedforward. by thegrate-bars 'froin the rear bar' 23, so that the feeder- 19 lfeed forward fuel to the gfate when the fuel level. on the front bar'` is below normal,vtlie possibility vthat too. much ,fuel .will .be fed.

`to the 'furnace at any time, as forinstance,

f in case the consumption-:should be much' below normal, is avoided. rOrdinarily the tendency' is for thebed 'of fuel to decrease in depth more rapidly in the -inner or rear part of the furnace thanlin the front, for the reason that the fuel will have' become much .more nearly reduced to'aslies when ithas r'eaclied said inner -portion,jso that, ordi- .feeding of the fuer but thisV will be only according `to requirements;

which usually', forms on the surface' oflth'e fuel, when soft coal is used, thus giving a i free draft therethrough and making the use vof a slice-bar unnecessary. z This latter rewhen it's levl'elis reduced by being consumed, or when the ash and clinkers are ,dumped may again deliver fuel to the bars; As thev ternatelyope'rating gratas which will only narily, there will always be 'so'nie forward A scribed', b'utalso acts to breakup the crust sult may be secured by operating the connecti-ng rods independently or simultaneously. l

s the clinkers will be delivered on the grate-bar 23, they may be'broken up by swinging said bar upwardly and frwardly at intervals. The clinkers, when broken up, may also be dumped into the ash-pit by drawing forwardly the rod 26. f

lVliile the downward swinging movement of grate-bars 3 and 4 is normally limited at l the horizontal position, ifvit is 'desired to dump the4 fuel on'the grate into the ash-pit, it is merely necessary to remove the sto'p-pins 15 from the rods T and 8, so that said bars `may be pushed rearwardly and the grate bars'swung downwardly, permitting the fuel to slide from them.

By employing j the particular form of grate-bars abovedescribed, an increased grate surface, through which the air may pass, is provided,.when .the bars are in raised, or partly raised position, by the provision of the draft slots therethrough, as the air will pass from the under side of the grate both through the top and front thereof. This action, together with the constant breaking up of the fuel, which occurs by the lifting and lowering of the bars, greatly assists in increasing` the draft.

vFrom the foregoing description it will be apparent that I provide a grate device which acts both as a mechanical stoker and as a mechanically operated the draft passages of the grate open to an extent sufficient to provide the necessary draft. It will further be observed that, with the above' described arrangement the fuel may be fed any distance, i. e., a furnace of any desired length may be employed, as the fuel may be fed from its front to its rear end and maintained at a uniform depth throughout its entire l length.

l. In a furnace, a series of horizontally disposed, transversely extending grate-bars adjacently arranged in parallelism, each pivotally supported to swing about ay longitudinal axis at its rear side, fuel-delivery means arranged to deliver fuel onto the first grate-bar of said series and operative only when the depth ofthe fuel on said bar is below the normal level to be maintained, and inoperative when said level is reached, automatically operating means ,to swing one set of alternate bais upwardly and then the other, to feed the fuel from said front bar toward the rear, andfuel retaining means adjacent therear bar of'said series for preventing rearward feeding of the fuel and to cause it to accumulate to the normal level from rear to front, .whereby the fuel may thereafter be automatically maintained at said normal level.

2. In a furnace, having a fuel-chamber at its front side, a series of horizontally disposed, transversely extending grate-bars adjacently arranged in parallelism, each pivotally supported to swing about a-loiigitudinal axis at its rear side, the front bar of said series being arranged adjacent said chamber to receive fuel therefrom, a nonpositively operating fuel delivering means in said chamber adapted and arranged to deliver fuel from said chamber on the said front bai', and operative only when the depth of the fuel on the latter is bel'ow a predetermined level. operating means to actuate said delivery means and to swing one of said alternate bars upwardly and then the other to feed the fuel toward the rear, and fuel retaining means directly in the rear of means to keep' said bars to cause the fuel to accumulate to a predetermined depth from rear to front and prevent feeding action of said delivery means except when said fuel depth isV reduced below said level.

3. In a furnace, having' a fuel-chamber in its front side, a series of horizontally disposed, transversely extending grate-bars ad jacently arranged in parallelism, eachpivotally supported to swing about a longitudinal axis at its rear side, the front bar of' said series being arranged adjacent said chamber, a fuel-retaining Wall at the rea" of said bars extending upwardly from th( level of the grate to lan extent sufficient to hold the. fuel at a. predetermined level, a non-positively operating fuel feeding means adapted and arranged to deliver the fuel from said chamber to the front grate-bar,

and operative only when the fuel on said bar is below said predetermined level, and operating means to actuate means and to swing one set of .alternate bars upwardly and then the other, to feed the 4fuel from said chamber toward said retaining Wall and to maintain a substaiitiallycoiistant fuel level.

.4. In a furnace, having a fuel-cliainber at its front side. a series-of horizontally disposed, transversely extending grate-bars adjacently arranged in parallelism, each pivotally supported to swing about a longitudinal axis at its rear side. the front bai' of only when the depth thereof is below they normal level, and fuel-retaining means arranged directly iii the rear of said bars for causing the fuel to accumulatel to a depth beyond which said bars aie inoperative to feed the fuel, whereby, as the fuel accumulates to said depth from rear to front, said bars and said feeding device become inoperative to feed the fuel. y

5. In a furnace, a series of horizontally disposed, transversely extending grate-bars adjacently arranged in parallelism, each pivotally supported to swing about a longitudinal axis at'its rear side. fuel-delivery meansr arranged to deliver fuel onto the first grate-bar of said series aiid operative only when the depth of the fuel on said` bar is below the normal level to be mainsaid feeding adjacent said front mined, and imdpmtve "Wwn oward the rem; andley from fear to front, Wheeby the fui may' ,N name 1550 fsw@ subsmlbmg;

W v MARMMAN, wils. 

